Forged Piston/block durability?

[Turbodave]

I’ve got the short block for my Rampage project sitting on a stand in my garage. It’s an 89 TII block, forged crank and rods with Venolia Pistons (forged). Everything has been freshly machined and I’ll be putting it back together soon. I had the machine shop bore the cylinders towards the tighter end of the spec listed by Venolia, but this is still a lot looser than the clearance stock cast pistons use.

I’ve got my 3cyl van sitting in the driveway and the motor I had planned on installing into it from the 89 Lancer is also only hitting on 3cyl. Now my thought was to temporarily run the TII in the van until I have time to go through a 2.5 for it. The TII will see an easy low boost stock head/turbo life in the van so I’m not worried about it breaking, but I am concerned about wear as it will probably live there for a year or so and the van will be driven daily, worst case probably 20k miles. I know the Venolias can be a little noisy when cold, has anyone had problems with wear in the bores from the extra piston clearances? I don’t want to rebuild this motor again before it takes up permanent residence in the Rampage.

[Turbofreak]

the bores won't wear nearly as much as the pistons.... I have heard a round about number of like 70-100K miles "max life" if using Synthetic with softer forged pistons 2618 like venolias with lots of clearance... another reason to have them coated with teflon on the skirt... tighten clearance and eliminate skirt wear and wobble... but as always... more $$$$

Why not just pull your "3 cyl" out and re-ring and bearing it with a hone job and one new piston.....

better than wasting your TII engine if something were to happen to it...

I dunno, just what I would do...

RYNO

[Turbodave]

Quote:

Originally Posted by Turbofreak Why not just pull your "3 cyl" out and re-ring and bearing it with a hone job and one new piston.....

I still haven't ruled that out, but I tend to go overboard on things so before you know it I'll be boring out the 2.5 and buying new pistons for it etc. Which is pretty much my plan anyhow (its got 185k on it..), but I was thinking of running the 2.2 in the van in the mean time, figured I would get the 2.2 broken in and work out any possible bugs with the short block. I'm afraid of building the short block only for it to sit on the stand for another year getting rusty.

Most likely I'll change my mind 100 more times before I actually pick up a wrench... The van actually runs ok on 3cyl, gets 21mpg and only uses 1qt of oil every 1,000miles, no smoke or anything. it's the rough idle and 40psi compression in that cyl that bugs me. (goes up to 120 when you pour a little oil in the bore).

[Turbofreak]

so.... jerk the head and put one new piston, one new ring set, and one new rod bearing on that one hole and be done with it....

right???

;-)

RYNO

I know exactly what you mean tho...

[glhsken]

Dave, You sound like me!!!

Wiseco's only require .0035" clearance T4556?? aluminum..

Ryan, Whenever I re-piston a car, id the cross hatching looks good.. I do not touch it. Never had a ring not seat. Always used Hastings moly rings.

[Turbodave]

Quote:

Originally Posted by glhsken Dave, You sound like me!!! Wiseco's only require .0035" clearance T4556?? aluminum.. Ryan, Whenever I re-piston a car, id the cross hatching looks good.. I do not touch it. Never had a ring not seat. Always used Hastings moly rings.

I don't think I've ever had a 2.2 or 2.5 apart that didn't have a good looking cross hatch, my ridge reamer has gotten rusty since I've started working on these cars.

I may go the pop in a piston route, It's certainly more in-line with my budget lately, but I don't have time to do a job twice either. Probably my first step will be to pull the head off and get a look at what's wrong inside...

Ken, the Wiseco's sound like a good part, I'll certainly consider them for the next forged piston motor I build.

[minimopar]

Dave,

With all the weird stuff that happened with that motor (hydrolocked with anti freeze, etc), are you sure it just didn't blow the headgasket? Does it pop the dipstick? I got my CSX with #4 blown and the piston slap wore a spot on the backside of the top of the bore. It honed out, but it took a while. The previous owner drove it for quite a while blown. Just something to consider....

I'd patch it up with a used piston and a new ring pack. Even if it doesn't seat all that great, you'll be on 3-3/4 pistons instead of 3. Of course, some people would say that you should reuse your rings too...

Then just build up the Lancer motor when you have the time into a 2.5L torque monster for that van....

[minimopar]

Just FYI, after my patch job on the CSX, the compression on #4 always read a little low compared to the others (115-115-115-110). After 25k, they all went up a little and read about the same now (about 120psi). I ran big gaps on my Venolias and the hatch marks on the bores are worn off where the piston skirts are.

[Turbodave]

Quote:

Originally Posted by minimopar Dave, With all the weird stuff that happened with that motor (hydrolocked with anti freeze, etc), are you sure it just didn't blow the headgasket? Does it pop the dipstick? I got my CSX with #4 blown and the piston slap wore a spot on the backside of the top of the bore. It honed out, but it took a while. The previous owner drove it for quite a while blown. Just something to consider.... I'd patch it up with a used piston and a new ring pack. Even if it doesn't seat all that great, you'll be on 3-3/4 pistons instead of 3. Of course, some people would say that you should reuse your rings too... Then just build up the Lancer motor when you have the time into a 2.5L torque monster for that van....

I never actually heard that Ron hydrolocked it, just that it overheated, wouldn't start and then was ok?

My plan is to finish Glen's Daytona, fix the trans in the Shadow and get the white R/T through emissions, then I'll rip the head off the van and see what's up with it.

[Una]

What's this? Venolia forged pistons will only go 100k miles? Where is this information, this should be posted somewhere, that's kind of important need to know information! Where can I buy better forged pistons? I'm trying to build the ultimate engine, I don't want pistons that are going to wear out long before the rest of the engine! Eeek!
Got links to information on this? And most importantly, who sells better pistons for our engines?

[Una]

Hello? Back up your FUD...

[Turbofreak]

Dale at Venolia told me this about the average venolia 2618 material forged piston endurance...

There are a couple of reasons for the estimated 100K mile life...

1. soft material... has to be soft to take detonation and extreme stress (high-HP)
2. Extra Bore clearance -wears the pistons faster and causes more bore wear also...meaning that the rings will give out quicker because of all the different stress angles on them...

Wisecos are very good pistons and many people are having great success with them, as with JE....

Truthfully speaking, it is tough to design a forged piston that is strong enough to withstand the rigors of everyday use without being too noisy or too brittle or too soft...

TIII engines did pretty well with this, because they were forged piston from the factory, but the forged pistons they run are quite a bit harder than the 2618 material... they may be 4032, which is a lot tougher, less expanding material for forged pistons, but it can't take quite the abuse the 2618 can...

Think of it like this... if you seriously think that your Turbododge will go 100K miles before breaking something major.... ;-) .... you might want to think about having the pistons coated on the skirts and tops and tightening up the bore clearance some....

RYNO

[Una]

Ahh, very informative. I understand completely. Makes sense. Thanks.

[minimopar]

Quote:

Originally Posted by Turbodave I never actually heard that Ron hydrolocked it, just that it overheated, wouldn't start and then was ok? My plan is to finish Glen's Daytona, fix the trans in the Shadow and get the white R/T through emissions, then I'll rip the head off the van and see what's up with it.

Yeah, he said that it overheated and later on (next day?) it wouldn't turn over. He pulled the plugs and cranked it over and it shot antifreeze 50ft in the air. Then it started fine and didn't use antifreeze anymore. Something like that.

Good luck with the Daytona and Shadow. Let me know if you do bearings. The slide hammer makes it much easier.